The National Basketball Referees Association admitted Sunday that LeBron James was fouled on the last play of regulation in the Los Angeles Lakers' loss to the Boston Celtics and called the mistake "gut-wrenching."

"Like everyone else, referees make mistakes," the union wrote in its tweet. "We made one at the end of last night's game and that is gut-wrenching for us. This play will weigh heavily and cause sleepless nights as we strive to be the best referees we can be."

James got the ball about 35 feet from the basket, with 4.1 seconds remaining in what was a tied game at Boston on Saturday night. He split two defenders as he got into the lane, then went airborne and got past Jayson Tatum. James laid the ball up with his left hand, Tatum clearly made contact with James' shooting arm, no foul was called and the game went to overtime.

Had a foul been called, James would have gone to the free-throw line with an opportunity to put the Lakers ahead with 1.8 seconds remaining. The Celtics wound up winning the game in overtime, 125-121.

"We got cheated tonight, honestly. ... It's unacceptable," Lakers forward Anthony Davis said after the game.

The NBA acknowledged shortly after the game that a foul should have been called -- "There was contact. At the time, during the game, we did not see a foul. The crew missed the play," crew chief Eric Lewis told a pool reporter -- and reaffirmed that Sunday in the report detailing calls made and missed in the final two minutes of regulation and overtime.

The Lakers entered Sunday 13th in the Western Conference at 23-27, only two games back of the final play-in spot and four games back of the fourth-place Los Angeles Clippers. But the Lakers have also spent virtually the entire season on the outside of the playoff picture.

"We don't have room for error," James said after Saturday's game. "And it's one of the best games we played all year. For it to fall on somebody else's judgment, or non-judgment, it's just ridiculous. It's ridiculous."

Neither James nor Davis will play in the Lakers' next game on Monday at Brooklyn, the team said. Injuries are the reason; James has left ankle soreness and Davis continues to deal with a right foot stress injury.

James reacted with no shortage of animation after the missed call on the Tatum play, immediately pointing to his arm and eventually slumping to the court, resting on his knees and elbows as he tried to come to grips with no foul being called. He also went to social media on Sunday to vent his frustration.

??‍♂️!!! I don't understand. I truly don't https://t.co/XgVDGRZ5Wa

— LeBron James (@KingJames) January 29, 2023

Lakers guard Patrick Beverley brought a camera onto the court during the ensuing stoppage to show Lewis an image of the contact; Beverley got a technical foul, and the Celtics wound up starting the overtime with a 106-105 lead because of the resulting free throw.

It marked at least the fourth time in recent weeks that the Lakers felt a late-game call went against them in what became a loss.

"I don't see it happening to nobody else," James said. "It's just weird."

Added Lakers coach Darvin Ham: "As much as you try not to put it on officiating, it's becoming increasingly difficult."

The Associated Press contributed to this story.